River Regulation Projects Research Articles

Experimental Study of Ice Jam Thickening under Dynamic Flow Conditions

River ice jams are a common occurrence on northern rivers, and their formation can present a severe flood risk to nearby communities. As more and more river regulation projects are developed to provide an alternative to fossil fuels for electrical power-generating capacity, our need to understand the mechanisms associated with ice jam formation under variable flow conditions becomes more vital. This is because, at present, hydropeaking operations are often severely curtailed during the ice-affected seasons due to concerns that sudden flow fluctuations might instigate ice jams and associated flooding. Here, an experimental investigation explores the effects of rapid increases in discharge on ice jam formation and evolution. It is found that the thickness of ice jams formed under highly dynamic flow conditions tend to be slightly thinner than those formed during steady carrier flows for comparable discharges. Also, despite the highly dynamic nature of these consolidation events, the resulting ice thicknesse...

Living Together with Nature. Farming on the River Flats in the Valley of the Tisza

In the past one thousand years that the Hungarians have been living here we find complex examples of use of the land in the Carpathian Basin, as a large region forming a uniform geographical, ecological and economic system. The Great Plain played a decisive role and, within this, the valley of the Tisza where we find the harmonious co-existence of land and man, water and man along the river, in the periodically inundated areas. In research into farming on the river flats, ethnological studies adopting a new approach brought new results in recent decades. Four levels or zones of farming can be distinguished along the Tisza: the river level, the river flats, the flood-free areas and the sandy hills following the line of the river. Ever since the Árpádian period economic activity has been carried out in the areas known as fok, the system of channels connecting the river and the low-lying river flats. The wet farming on the river flats and the dry farming on the flood-free areas are mutually complementary forms of land use. The big river regulation projects carried out in the 19th century transformed the landscape and brought substantial changes in the methods and possibilities of farming.

Effects of river regulation and diversion on marine fish and invertebrates

AbstractThe effects of freshwater regulation and diversion on the adult and larval stages of fish and invertebrates in coastal marine waters are reviewed.Potential impacts of river modification are highlighted based on our present understanding of the role of fresh water on the physical, chemical and biological processes on the marine environment. These include effects on migration patterns, spawning habitat, species diversity, water quality and distribution and production of lower trophic levels. The effect of dams on anadromous and catadromous fish are also presented.We discuss in detail the marine response to specific river regulation projects on the Nile, Indus and rivers flowing into the Black Sea, San Francisco Bay and James Bay in Canada. A decline in some coastal fisheries with an overall negative impact on the biota is generally associated with reductions in freshwater flow.Extensive ecological considerations are needed during the planning stage of large‐scale freshwater modification projects to minimize potential impacts.

Hydrologic aspects of limnology in South Africa

Because of the variability of rainfall and lack of extensive groundwater resources, concentrations of population in South Africa give rise to the need for river regulation projects. The inter-related effects on inland waters of regulation by storage and of degradation as a result of use by man are examined. Particular attention is paid to the Vaal basin, the water resources of which are currently being exploited to the direct advantage of its six million inhabitants.